This invention lies in the field of windmills and wind operated devices generally. More specifically, it concerns rotating cylindrical structures as contrasted with rotating planar structures, such as the conventional windmills.
In the prior art there has been some work done on the use of curved blades, or curved winged rotors, which are adapted to rotate about a vertical axis at the point where the curved wings are joined together. The S-shaped vane or wings are the most common form of prior art. However, these have a serious disadvantage in that wind blowing into one concave portion creates a positive pressure, while a negative pressure is simultaneously generated in the opposite one, restraining the rotation of the rotor.
In the prior art it has been discovered that by separating the two halves of the S-shaped wing, that is, having the two semi-cylinders overlap one another, then a continuous flow of wind into one semi-cylinder and then into the second, eliminates the negative pressure and creates a positive pressure in the concave portions of both wings, and therefore provides additional torque.
In this invention, use is made of a combination of the S-type wings and the overlapped wings to provide additional torque.